Cloud Smoke Ink.
Ordinary families rarely used it, nor could they afford to. It was generally reserved for the high and mighty to write highly confidential letters.
After the letter was read, it would be soaked in cold water, leaving not a single trace behind—just like a passing cloud of smoke.
Liang Wan was conflicted.
As soon as Gu Yu entered the inner room, she saw Liang Wan kneeling on the daybed, staring blankly at a letter in her hands. "My lady?"
Liang Wan gritted her teeth. "Go fetch me a basin of water."
By the time Gu Yu returned with the water, Liang Wan was already hunched over the table.
"Go stand guard at the door. Don't let anyone in."
She didn't even look up, her eyes completely captivated by the letter.
It was the one that had fallen from the plaque.
Gu Yu set down the basin, then retreated outside and shut the door firmly.
The night grew deeper, and all was quiet.
